function

Discussion in 'Math' started by fpoint, Mar 28, 2015.

  1. fpoint

    Thread Starter New Member

    Mar 28, 2015
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    On the x-coordinate, there is straight line AB, point A is fixed on the x-coordinate, point B is located at any point x-coordinates, to describe this function ?
     
  2. MrChips

    Moderator

    Oct 2, 2009
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    Do you know the equation of a straight line?
     
  3. Papabravo

    Expert

    Feb 24, 2006
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    The point slope form is:

    (y - y0) = m(x - x0)

    (x0, y0) are the coordinates of one of the points
    if (x1, y1) are the coordinates of another point then
    m = (y1 - y0) / (x1 - x0)
     
  4. WBahn

    Moderator

    Mar 31, 2012
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    You only talk about the x-coordinate. Are you working with a function in an x-y plane, or just on a number line?

    A picture would really help.

    As I try to interpret this, it only makes sense if it is reworded as:

    On the x-y plane a function is described by a straight line AB. The point A is fixed at coordinate <x0,y0>, The point B is located at an arbitrary point, <x1,y1>, What is the function, y=f(x), that describes this function.

    Does that sound close to what you are being asked for?

    If so, then is the function supposed to match only the portion of the line between A and B, or the entire line that passes through A and B?
     
  5. fpoint

    Thread Starter New Member

    Mar 28, 2015
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    x-coordinate represents
    \mathbb{R}^1
    there is no need for labeling (x1,y1) plane represents
    \mathbb{R}^2
    function can be solved in the x-coordinate ( indicated in red letters )
    A=a_{x.} , B=x_{x.} , AB=function ?
    label (x.) - takes place in the x-coordinate
     
  6. WBahn

    Moderator

    Mar 31, 2012
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    There's no red letters in your post, so I'm not sure what you were trying to indicate with them.

    I think I am following what you are doing. I'm not too comfortable with the math set-theoretic notation, so I may not be following you completely.

    If I am, then you are basically saying that you looking for a function f(x) such that f(x_a) = A, f(x_x) = B, and the f(x) is linear. Is that correct?

    Also, you need to provide YOUR best attempt to solve YOUR homework. Not only is that expected, but it goes a long way toward making sure that we are on the same page.
     
    cmartinez likes this.
  7. amilton542

    Active Member

    Nov 13, 2010
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    There are two cases:

    1) Any two given points that lie on the line.

    2) The slope and a point on the line.

    Post #3 is your solution.
     
  8. fpoint

    Thread Starter New Member

    Mar 28, 2015
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    a) y_{x.}=|a_{x.}-x_{x.}|
    b) y_{x.}=-|a_{x.}-x_{x.}|
    c) y_{x.}=a_{x.}-x_{x.}
    d) y_{x.}=x_{x.}-a_{x.}|
    e) y_{x.}=\{|a_{x.}-x_{x.}|\}\cup\{-|a_{x.}-x_{x.}|\}
    x. - place (label for x-coordinate)

    Mathematics official says geometric objects measures must be positive numbers, say my function to geometric objects measures may be negative numbers


    question - how to make it look proceedings graphics of my functions in the plane (Cartesian coordinate system)?
     
  9. studiot

    AAC Fanatic!

    Nov 9, 2007
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    Well your mathematics teacher is wrong.
    Zero is a valid value.
    Zero is neither negative nor positive.

    He or she may want non-negative values, but that is not the same as positive definite.

    So your modulus function will do this

    {y_x} =\left| {{a_x} - \left. {{X_x}} \right|} \right.

    alternatively you might like to know that we often use this one instead since the modulus function is not differentiable at x=0.

    {y_x} = \sqrt {{{\left( {{a_x} - {X_x}} \right)}^2}}

    but this one is.[/quote]
     
    Last edited: Apr 6, 2015
  10. fpoint

    Thread Starter New Member

    Mar 28, 2015
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    The mapping function from the x-coordinates of the plane (Cartesian coordinate system)
    y = x-a, x and a remain on the x-coordinate, y goes to the y-coordinate.
    view photo
    https://pkxnqg.bn1302.livefilestore...WSh5idkVdC-swrTkqYaXV8fmts9x7Ks/ii.png?psid=1
    the lines of x and a parallel to the y-coordinates
    line of y parallel to the x-coordinate
    formed at the intersection of real points A and B
    points A and B are combined and gets straight line AB
    is given by x = 4, a = 2, y = 2
    Repeat for x = 3.5, a = 2, y = 1.5, view photo
    formed at the intersection of real points C and D
    points C and D are combined and received straight line CD
    https://befwwg.bn1302.livefilestore...DKraCcJKIy-UHkR4VeCHL_PmPvJTSMeM/i.png?psid=1
    connect the dots AC (BD) straight lines AB and CD
    ABDC points form the surface of 4≥x≥3.5
    Draw a graph of the function at the current proceedings for
    a) y=|a-x|
    b) y=-|a-x|
    c) y=a-x
    d) y=x-a
    e) y={|a-x|}\cup{-|a-x|}
     
  11. fpoint

    Thread Starter New Member

    Mar 28, 2015
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    y=|2-x|
    graph, the red surface
    https://cfxpzq.bn1302.livefilestore...duf35TDz7kJFlvpinPGfiGmOhMAVbDw/01.png?psid=1

    b) y=-|2-x|
    graph, the red surface
    https://nq6hfq.bn1302.livefilestore...xhUjRvcF6i6WXHS-qNoA1O50MwSx-Kw/02.png?psid=1


    c) y=2-x
    graph, the red surface
    https://0nivia.bn1302.livefilestore...qqqkUyEXwbMEkel843ZQ20Rq__x6V-A/03.png?psid=1

    d) y=x-2
    graph, the red surface
    https://d6pekg.bn1302.livefilestore...0AJlHabqjfVBAgiGORjpymT7vzmMKCA/04.png?psid=1

    e) y={|2-x|}\cup{-|2-x|}
    graph, the red surface
    https://qhdsnq.bn1302.livefilestore...HeXxWALY-BwcLW4G5ObhnQSYfKmEaVQ/05.png?psid=1

    which are geometric objects obtained for valuesx and y , shape a≥x≥b ( a≥y≥b ) ? , you have a graph
     
  12. fpoint

    Thread Starter New Member

    Mar 28, 2015
    11
    0
    a)y_{x.}=|a_{x.}-x_{x.}|
    b)y_{x.}=-|a_{x.}-x_{x.}|, the same graph is reversed only to 180^o , and relates to a negative value y
    the scene (x.)x-coordinates , (y.)y-coordinates ,( xy.)plane
    Graph functions y_{x.}\rightarrow y_{y.} , mapped straight line (y_{y.},a_{x.},x_{x.})\rightarrow(a_{xy.}x_{xy.})
    2≥y≥0 ( The general form b≥y≥0 , b>0 ) rectangular isosceles triangle
    https://2bl1tq.bn1302.livefilestore...kPva7zBN1RUVuKqNL12VYCgSDrGVr0A/y1.png?psid=1

    3≥y≥1 ( The general form c≥y≥b , b>0 , c>0 ) regular trapeze
    https://dc4d8a.bn1302.livefilestore...WL9PS8DTbYrpR0fD2Vhx9lCacxIjf8g/y2.png?psid=1

    1≥x≥-1 ( The general form c≥x≥b x<a , c≥x≥b x>a ) rectangular trapeze
    https://o9amca.bn1302.livefilestore...FCWt4FDy7sqTIZNX57SWFbuE4v6HR6w/y3.png?psid=1

    6≥x≥-1 ( The general form c≥x≥b , b>a , c<a , |b|\neq|c|) pentagon
    https://pkxoqg.bn1302.livefilestore...ThLPbQyTNzHDTKaz5o26xnOhTE2PD9Q/y4.png?psid=1
    more geometric objects that can be obtained ???
     
  13. fpoint

    Thread Starter New Member

    Mar 28, 2015
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  14. studiot

    AAC Fanatic!

    Nov 9, 2007
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    I remember socratus used to post threads in this fashion, until no one bothered to read or answer them any more.
     
  15. fpoint

    Thread Starter New Member

    Mar 28, 2015
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  16. WBahn

    Moderator

    Mar 31, 2012
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    Ah, yes. That was the socratus that associated themselves, rather appropriately, with a particularly dense metal, right?

    You lasted longer than I did.
     
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